function setImagePreviews(avalue) {

        var docObj = document.getElementById("doc");
        var dd = document.getElementById("dd");
        dd.innerHTML = "";
        var fileList = docObj.files;
        for (var i = 0; i < fileList.length; i++) {            
            dd.innerHTML += "<div style='float:left;width:150px;' > <img id='img" + i + "' /> </div>";
            var imgObjPreview = document.getElementById("img"+i); 
            if (docObj.files && docObj.files[i]) {
                //火狐下，直接设img属性
                imgObjPreview.style.display = 'block';
                imgObjPreview.style.width = '100%';
                // imgObjPreview.style.height = '50%';

                // imgObjPreview.src = docObj.files[0].getAsDataURL();

                //火狐7以上版本不能用上面的getAsDataURL()方式获取，需要一下方式
                imgObjPreview.src = window.URL.createObjectURL(docObj.files[i]);
            }
            else {
                //IE下，使用滤镜
                docObj.select();
                var imgSrc = document.selection.createRange().text;
                alert(imgSrc);
                var localImagId = document.getElementById("img" + i);
                //必须设置初始大小
                localImagId.style.width = "100%";
                // localImagId.style.height = "50%";
                //图片异常的捕捉，防止用户修改后缀来伪造图片
                try {
                    localImagId.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)";
                    localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc;
                }
                catch (e) {
                    alert("您上传的图片格式不正确，请重新选择!");
                    return false;
                }
                imgObjPreview.style.display = 'none';
                document.selection.empty();
            }

        }  
        return true;
    }
